The language of birds: 5.2 The functional use of sounds by a trained parrot

A remarkable case of avian vocal learning has occurred in a scientific
laboratory in the U.S.A. It concerns a talking African grey parrot
called Alex trained by Dr. Irene Pepperberg. To quote from Dr. Pepperberg's
account, Alex "is able to participate in some forms of inter-species
communication" (by which the author means she can converse
with the bird!). Alex is capable of demonstrating more than simply
the ability to imitate human speech patterns.

But what exactly can Alex do? The bird was trained to identify vocally certain objects by name, e.g. "key" and "paper". It was also taught to name certain colours such as "green" and "blue", and certain shapes with labels like "three corner" (easier to learn than triangle) in order to categorise objects with respect to colour and shape. It also learnt to recognise quantities of objects up to five and learnt the functional use of the word "no" as well as phrases such as "come here" and "wanna go". After five years it had been taught a functional repertoire of about 40 vocalisations.

When an object was held up before the bird, it identified the object accurately eight times out of ten. His most frequent errors -and they account for the majority - was either the omission of the colour or shape adjectives, or the unclear pronunciation of the colour adjectives. For example, when the trainer held up a green key and said "What's this?" Alex answered "green key" only 69% of the times. If the answer that he gave was simply "key" as it often was, the trainer then put the question "what colour key?". The bird usually got it right second try and raised its score from 69% to 94%. When randomly shown unfamiliar objects of familiar colours, the bird could not, of course, identify the objects, but invariably got the colour right.

Whenever he incorrectly identified an object, Alex was told "no ". After about 18 months of training, he began to use the word to his trainer when he appeared to wish not to be handled. Trainers then started to use the word "no" when refusing to relinquish an item desired by the parrot. Soon Alex would use the word "no". When refusing to identify a proffered object, he would say "no"; also when he had finished with his water, and when tossing an unwanted toy back at a trainer! The following is an excerpt transcribed from a tape and illustrating how the bird uses the word "no". It appears that Alex is using the word in order to refuse one task so that he can request a preferred item, a piece of four-cornered wood:

"No" is also employed to reject unacceptably small pieces of food, and to reject toys apparently too worn to be of interest. In many cases the refusals to identify or relinquish are accompanied by the turning of his head away from the trainer.

Besides using words in the use of which he has been trained, this African grey parrot will spontaneously but meaningfully use other words that it has picked up. For example, although he had not been trained to produce labels for the various foods, he will "request" food items or objects by speaking their names, prefaced by "want". If a trainer takes a particularly popular object, a cork, from a drawer and Alex sees it, he will say "want cork". He will also ask for objects not in view. And if a wrong object is proffered, he may either say "no" and refuse to take it, or he may briefly accept and then throw it back! He will call for particular "foods" or "water", even for "nut" or "corn".

Perhaps the most telling (forgive the pun) achievement of all is Alex's ability, although limited, to innovate simple combinations of words. For example, having previously been trained to identify certain objects as "green" and a clothes peg as the object "peg wood" (but never as a green one) the bird was offered a green clothes peg. He said "green wood, peg wood". He should have said "green peg wood" but he was linking phrases already in his vocabulary. Later he identified on first-ever presentation "blue peg wood", "green cork" and "blue hide" ("hide" is American parrot for leather). To segment phrases and recombine the elements in this way is to begin to meet one crucial criterion in the definition of true language. This parrot combined words in a novel, untutored way and described a new object. The remarkable work with Alex is continuing.